To commemorate the 50th anniversay of ARPA, Vanity Fair “set out to do something that has never been done: to compile an oral history, speaking with scores of people involved in every stage of the Internet’s development, from the 1950s onward.” Here’s Bob Metcalfe on his first demo of Arpanet to AT&T executives in 1972:

Imagine a bearded grad student being handed a dozen AT&T executives,
all in pin-striped suits and quite a bit older and cooler. And I’m
giving them a tour. And when I say a tour, they’re standing behind
me while I’m typing on one of these terminals. I’m traveling around
the Arpanet showing them: Ooh, look. You can do this. And I’m in
U.C.L.A. in Los Angeles now. And now I’m in San Francisco. And now
I’m in Chicago. And now I’m in Cambridge, Massachusetts — isn’t this
cool? And as I’m giving my demo, the damned thing crashed.

And I turned around to look at these 10, 12 AT&T suits, and they
were all laughing. And it was in that moment that AT&T became my
bête noire, because I realized in that moment that these sons of
bitches were rooting against me.